My stutter was at its worst when I was maybe 13 ish, now I’m 21 and each year it’s gotten better and better to now where people only notice it if I’m stressed, tired, or hungry. I echo other comments about mindset and self perception being very important. Outside of traditional speech therapy, I did hypnosis and shrooms and found those to be pretty helpful too. It’s all a matter of learning how to control your stutter and not letting it control you